Diversity Combining and Piezoelectric Beam Steering for MultiElement

Diversity Combining and Piezoelectric Beam Steering for Multi-Element VLC Networks Presenter: Yusuf Said Eroglu Authors: Yusuf Said Eroglu, Ismail Guvenc, Alphan Sahin, Murat Yuksel, and Nezih Pala

Outline • Background • Multi-Element VLC Transmitters and Receivers • System Model • Transmitter And Receiver Architectures • Combining Techniques • • • Simulation Results Piezoelectric Beam Steering Conclusion Future Studies Q&A

Background • Multi-LED transmitters • • Angle diversity Serves many users Easy to install and maintain High accuracy localization • Multi-PD receivers • Provides better SINR by utilizing many PDs • Space diversity

Objectives • SINR performance of the multi-LED transmitters • Achievable SINRs when it is used with multi-PD receiver • Optimal parameters for the multi-PD receiver • Evaluate with computer simulations

System Model – Tx and Rx Architectures • Transmitters: • Single-LED and 7 -LED • Tilt angle of LEDs: α • LED directivity index i a)a)The Thetop topviewof of 7 -LED transmitter, andααangle betweencenterand andside. LEDs. • Receivers: • • • Single-PD 3 -PD 7 -PD • Field of view: βFOV • Tilt angle of PDs: β 3 -PD receiver with βFOV and β angles

System Model – Combining Schemes Four receiver combining schemes: Selective Best (SBC), Equal Gain (EGC), Maximum Ratio (MRC) and Optimal Combining (OPC). For Maximum Ratio Combining (MRC) Single-PD For Multi-PD receivers For Optimal Combining (OPC) For Selective Best Combining (SBC), wp is either 1 or 0. For Equal Gain Combining (EGC), wp = 1 for all PDs.

Simulation Results – SINR CDFs 3 -PD and 7 -PD SBC 3 -PD MRC and OPC Single-PD 7 -PD MRC 3 -PD EGC 7 -PD OPC For single-LED transmitter configuration

Simulation Results – SINR CDFs 3 -PD SBC and MRC 7 -PD SBC and MRC 3 -PD OPC Single-PD and EGC 7 -PD OPC For 7 -LED transmitter configuration

Simulation Results – Optimal Parameters %50 SINR 3 PD %50 SINR 7 PD %5 SINR 3 PD %5 SINR 7 PD %50 SINR Single PD %5 SINR Single PD 5% and 50% SINR for single-LED transmitter vs different βFOV values

Simulation Results – Optimal Parameters %50 SINR 7 PD %50 SINR 3 PD %50 SINR Single PD %5 SINR 3 PD %5 SINR Single PD 5% and 50% SINR for 7 -LED transmitter vs different βFOV values

Piezoelectric Beam Steering • LEDs will be steered to track the location of the receiver • Assuming known location

Piezoelectric Beam Steering SINR is especially improved at cell edge, which will provide better link during handover.

Conclusion • SINR performances of different multi-PD combining schemes are investigated for different transmitter structures • OPC is particularly found to be more efficient for multi-LED transmitters • Optimal parameters for multi-PD receivers are studied • Optimal FOV and tilt angle increases when multi-LED transmitters are used • Piezoelectric beam steering is proposed to improve SINR further • Up to 7 d. B SINR gain at low SINR region with 10° tilt

Future Studies • Maximum sum rate • Fairness • Qo. S guarantees Optimal assignment of LEDs to users

Q&A • Thank you for listening!